• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.225-228
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• 2000

Addition effects of metal oxide on the characteristics of infrared radiator of porous cordierite have been investigated. The porosity was increased with adding the graphite for 2MgO $.$ 2A1$_2$O$_3$$.$5SiO$_2$. The microstructure and the spectral emissivity were investigated as a function of metal oxide additives. The prosity and the emissivity were decreased with increasing amounts of CuO additives. The prosity and the emissivity were increased with increasing amounts of CoO, MnO$_2$ additives. The infrared radiator of cordierite system which spectral emissivity was 0.927 and 0.928 at from 5$\mu\textrm{m}$ to 20$\mu\textrm{m}$ wavelength as a 9wt% of CoO and MnO$_2$ additives.

• 대기
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• 제25권4호
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• pp.601-610
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• 2015

This study measured the emissivity spectra of 5 major rock-forming minerals using a Fourier Transform Infrared (FT-IR) spectrometer in the spectral region of $650{\sim}1400cm^{-1}$. The mineral samples are quartz, albite, bytownite, anorthite, and sandstone. We compared emissivity spectra measured in this study with spectra provided by Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Arizona State University (ASU). The spectral features of emissivity such as Reststrahlen Band (RB) and Christiansen Feature (CF) locations were compared. Results showed that both CF and RB locations of emissivity spectra measured in this study were similar to those from ASTER and ASU. In the case of quartz, the RB was occurred in the region of $700{\sim}850cm^{-1}$ and $1050{\sim}1250cm^{-1}$. The spectral position of emissivity peak was in good agreement with the location of ASTER and ASU. For plagioclase (albite, bytownite, and anorthite), the spectral location of CF was shifted toward larger wavenumber and the emissivity value was increased in the region of $870{\sim}1200cm^{-1}$ with Ca percentage. The CF of anorthite and bytownite was occurred at $1245.79cm^{-1}$, and that of albite was occurred at $1283.79cm^{-1}$. We also confirmed that emissivity feature of sandstone includes both emissivity features of quartz and calcite. However, there were some differences in the magnitude of emissivity and locations of RB and CF. These were due to the differences in measurement methods, and differences in particle size and temperature of samples.

• 대한조선학회논문집
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• 제44권1호
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• pp.40-47
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• 2007

This study is focused on developing a software that predicts the temperature distribution and infrared Emission from 30 objects considering the solar radiation through the atmosphere. The solar radiation through the atmosphere is modeled by using the well-known LOWTRAN7 code. Surface temperature information is essential for generating the infrared scene of the object. Predictions of the transient surface temperature and the infrared emission from a naval ship by using the software developed here show fairly good results by representing the typical temperature and emitted radiance distributions expected for the naval ship considered in mid latitude. Emissivity of each material is appeared to be an important parameter for recognizing the target in Infrared band region. The numerical results also show that the low emissivity surface on the heat source can be helpful in reducing the IR image contrast as compared to the background sea.

• Journal of the Korean Wood Science and Technology
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• 제37권5호
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• pp.440-450
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• 2009

In case of wood flooring, the high emissivity would be one of the most important properties especially as the cover material of underfloor heating system. The FIR (Far Infrared) materials such as wood emit FIR energy by heating, which has been used as the medical therapy such as dry sauna. This research investigated the emissivity and the emission power of wood composites by comparing the amount of the three heat transfer modes transferred by infrared radiation which came from the increased temperature of the bottom board of the plywood box by the heater. The results showed the value of radiation mode was the highest mode for the plywood box, and the convection mode was the main mode for the aluminum box. The rate of convection was 81.8% in the aluminum box and 48.2% in the plywood box, respectively. In case of the rate of radiation, the aluminum box showed only 15.4% and the plywood box showed 51%. The emissivity and the emission power of birch plywood showed the same values as those of wood. The amount of energy required for the temperature rising of water within vial in the aluminum box and in the plywood box were 3.32 kJ and 6.70 kJ respectively, which showed that the vial temperature of the plywood box was two times higher than that of the aluminum box.

• 한국전산구조공학회논문집
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• 제29권5호
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• pp.455-461
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• 2016

적외선을 이용한 무기체계의 발달로 인해 항공기의 생존은 큰 위협에 직면해 있다. 따라서 항공기의 생존성 향상을 위해서 적외선 스텔스 기술이 매우 중요하다. 본 논문에서는 수치해석을 통해 실제 비행환경에서의 항공기 표면온도 및 주위 배경에 따른 적외선 신호를 분석하고 이를 바탕으로 적외선 스텔스를 위한 항공기 표면 구조체 방사율의 가이드라인을 제시하고 그 성능을 검증하고자 한다. 수치해석 결과, 주위 배경에 따라서 항공기 표면 방사율을 최적화한다면 항공기와 배경간의 복사대비강도를 감소시킬 수 있음을 확인하였다.

• 한국표면공학회지
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• 제36권5호
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• pp.406-412
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• 2003

FT-IR and thermography were used to investigate the infrared radiation characteristic of SiO$_2$ film and SiO$_2$/Fe$_2$O$_3$film coated on aluminum. Through FT-TR spectrum, SiO$_2$film showed high infrared absorption in accordance with the stretching vibration of Si-O-Si, and as$ Fe_2$$O_3$was mixed additional absorption band appeared resulting from the stretching vibration of Fe-O at $590cm^{-1}$ and the bond of Si-O-Fe at $900 cm^{-1}$ The two kinds of film measured by the integration method and the reflective method coincided with each other in the wavelength area of infrared absorption and radiation, and corresponded well with Kirchhoff's law as the infrared emissivity is high in wavelength where infrared absorption rate is high. The emissivity of $SiO_2$ film was 0.65 and that of $SiO_2$/Fe$_2$$O_3$film was 0.77, so the addition of$ Fe_2$$O_3$ raised the infrared emissivity by approximately 13%.$ SiO_2$$Fe_2$$O_3$ film is efficient as an infrared radiator at below $100^{\circ}C$. The temperature of heat radiation after 7 minutes was 117$^{\circ}C$ in aluminum plate and $155^{\circ}C$ in $SiO_2$$Fe_2$$O_3$ film, $38^{\circ}C$ higher than the former.

• 비파괴검사학회지
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• 제29권5호
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• pp.421-426
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• 2009

열화상 카메라와 대상물의 측정 위치에 따른 방사각도에 따라 방사율은 달라지게 된다. 이로 인해 열화상 시스템을 이용한 온도 측정시 나타나는 온도 분포는 절대적 온도로 볼 수 없다. 대상체의 실제 표면 온도가 일정하더라도 열화상 카메라로 측정된 온도는 방사율 값에 따라 오차를 가지게 된다. 본 논문에서는 동일 온도로 가열된 원통 형태를 가지는 대상체와 평면 형태를 가지는 대상체의 온도를 열화상 카메라를 이용하여 측정하였다. 측정된 표면 온도값을 통하여 화각에 의한 방사율 보정표와 방사각도의 영향에 의한 반사율 보정식을 구하였으며 이를 바탕으로 측정 온도의 오차보정을 수행하였다. 그리고 방사 각도와 화각에 따른 온도 영향을 원자력 배관의 결함 검출에 적용하여 더욱 신뢰성 있는 표면 온도값을 획득하였다.

• 한국전산구조공학회논문집
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• 제30권2호
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• pp.179-184
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• 2017

적외선 유도 무기의 급속한 발달로 인해 현대 장갑 차량의 생존성은 크게 위협 받고 있다. 따라서 적외선 신호를 줄여 탐지가능성을 줄이는 것이 지상 장갑 차량의 생존성 향상을 위해 반드시 필요하다. 이러한 목적으로 본 연구는 수치해석을 사용해 차량 적외선 신호의 시간 및 탐지 위치별 특성을 분석하였다. 그 결과 가장 낮은 대비복사강도를 보이는 방사율이 시간 및 탐지 위치별로 상이하며 적외선 신호를 효과적으로 저감하기 위해서는 차량 부위별로 다른 방사율을 갖는 제어 구조를 적용해야 할 것이다.

• 대한원격탐사학회지
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• 제32권5호
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• pp.423-434
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• 2016

적외선을 이용한 지표 온도 추정 및 변화 탐지를 위해서는 해당 파장대역의 각 센서에 따른 지표 복사율 추정 및 배경값에 대한 확보가 필요하다. 이 연구는 위성 영상으로부터 한반도에서의 중파장적외선 복사율 산출방법에 대한 제안 및 토지피복 종류별 대표 복사율을 산출하여 한반도 배경값을 제시할 수 있다. 중파장적외선 복사율을 추정하기 위해 Visible Infrared Imaging Radiometer Suite(VIIRS)의 $3.74{\mu}m$ 파장 대역 밴드4 영상에 Temperature Independent Spectral Indices(TISI) 방법을 적용하여 복사율을 계산하였으며, 또한 이와 비교하기 위해 Advanced Spaceborne Thermal Emission Reflection Radiometer(ASTER) spectral library로부터 토지피복에 따른 복사율도 계산하였다. 그 결과 활엽수립(0.958) 및 혼합림(0.955) 지역의 연평균 복사율이 가장 높았으며 농지(0.925) 및 자연식생(0.935) 지역보다는 약 2-3% 높게 나타났다. 도심지역의 경우 0.914로 가장 낮으며 연간 변화율이 1%인 다른 지역과는 달리 약 2%로 그 편차가 크다. ASTER spectral library와 비교한 결과 위성영상에서 추정한 중파장적외선 복사율은 동일한 토지 피복에 비해 약 2-3% 낮게 나타나는데, 이는 실제 지표면이 불균질한 점 외 기타 다양한 원인에 의한 것으로 추정된다. 이러한 연구 결과는 중파장적외선 영상을 이용하여 지표온도 추정 및 토지피복도의 계절 및 외부환경 변화에 의한 한반도 중파장적외선 복사율의 변화 특성을 이해하는데 기초 자료로 활용될 것이다.

• 한국세라믹학회지
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• 제45권7호
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• pp.387-394
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• 2008

The Physical property changes of calcined clay by carburization were investigated studied. The carburization mechanism is the penetration of carbon which occurred during incomplete fuel combustion into crevice of clay structure. The experiments for elasticity and freeze-thaw resistance were conducted, and the results can be summarized as follows: Dynamic modulus of elasticity and also freeze-thaw resistance of calcined clay by carburization treatment increased more than 92% after testing 300 cycle, which was more improved than 88% of calcined clay. Therefore, it can decrease the possibility of winter-sowing, which is one the weakness of calcined clay. It is on the basis of the fact that the porosity of calcined clay by carburization treatment is about 12%, which indicates smaller pore spaces comparing with the 14% of porosity of calcined clay and those values were calculated by apparent porosity show and also supported by SEM images. Infrared emissivity of calcined clay by carburization treatment and calcined clay were respectively 0.92 and 0.9l at $80^{\circ}C$. However, those values were 0.91 and 0.88 at $200^{\circ}C$, which means infrared emissivity of calcined clay by carburization treatment shows 3.6% higher than the calcined clay. Moreover, within the wavelength range from 3 to $7\;{\mu}m$, while the calcined clay had low infrared emissivity, the calcined clay by carburization treatment had increased infrared emissivity. It is inferred that it was affected by carbon element that has high infrared absorptivity within this wavelength range.